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<td class="header">&nbsp;Speckle Divergence</td>
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<h3>Urban Area Mapping with Speckle Divergence<span style="font-family: Symbol;"><span style=""><span style="font-family: &quot;Times&quot;,New Roman; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"></span></span></span></h3>
<p>Local speckle characteristics can provide a texture layer that
highlights built-up areas.<span style="font-family: Symbol;"><span style=""><span style="font-family: &quot;Times&quot;,New Roman; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"></span></span></span> Local
deviation from the fully developed speckle&#8212;speckle
divergence <i style="">D<sub>x,y&nbsp;</sub></i>increases
with a rising amount of true structures within the resolution cell.<span style="font-family: Symbol;"><span style=""><span style="font-family: &quot;Times&quot;,New Roman; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal;">&nbsp;&nbsp;&nbsp;
</span></span></span>The variation of structures
leads to a local heterogeneity that gives urban areas a very specific
and distinct appearance in SAR images. </p>
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<p class="MsoNormal" style="margin-left: 18pt;">T.
Esch, M. Thiel, A. Schenk, A. Roth, A. M�ller, and S. Dech,
"Delineation of Urban Footprints From TerraSAR-X Data by Analyzing
Speckle Characteristics and Intensity Information," IEEE Transactions
on Geoscience and Remote Sensing, vol. 48, no. 2, pp. 905-916, 2010.</p>
<p class="MsoNormal" style="margin-left: 18pt;">T.
Esch and A. Roth, &#8220;Semi-automated classification of urban areas by
means of high resolution radar data,&#8221; in Proc. ISPRS Congr., 2004, pp.
478&#8211;482.</p>
<p class="MsoNormal" style="margin-left: 18pt;">M.
Stasolla and P. Gamba, &#8220;Spatial indexes for the extraction of formal
and informal human settlements from high-resolution SAR images,&#8221; IEEE
J. Sel. Topics Appl. Earth Obs. Remote Sens., vol. 1, no. 2, pp.
98&#8211;106, Jun. 2008.</p>
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